1. Field of the Invention
The invention relates to a composite pressure vessel with a plastic liner for storing gaseous media under pressure.
2. Discussion of the Prior Art
EP European reference 0 753 700 A1 discloses a composite pressure vessel forming the generic type. It comprises a plastic liner having two neck pieces arranged in the neck region, and having a winding of a fiber composite material that reinforces the liner. At least one neck piece is designed in such a way that it can accommodate a screw-in valve having a cylindrical or conical thread. Both neck pieces are provided, in the end region facing the pressure vessel, with a flat, frustoconical collar which is surrounded on the inside by the liner and on the outside by the reinforcing winding. In the region facing the liner, both neck pieces have an internally threaded section which interacts with an externally threaded section arranged on that region of the liner which is designed as the neck. The neck piece that accommodates a valve has, on the inside in the thread-free region adjacent to the internally threaded section, an annular groove to accommodate a sealing element. This is adjoined by a further internally threaded section to accommodate the valve. As a safeguard against rotation, the neck piece that accommodates the valve is provided with a wrench attachment on the outside.
This design is only partially suitable to meet the special requirements which are placed on pressure vessels having a filling pressure up to 300 bar. This applies in particular to the sealing in the neck region and to impact stressing of this region.